标况下将448L氯化氢溶于1L水(纯水的密度为1.0g/cm3),所得溶液密度1.1g/cm3,溶液中氯化氢的浓度为( )
A:11.7mol/L
B:12.7mol/L
C:13.7mol/L
D:14.7mol/L
用力推课桌的下部,课桌会沿地面滑动,而推课桌的上部,则课桌可能会翻倒,这说明力的作用效果( )
— Come on! You could recite (背诵) the long poem ____ difficulty.
— Thanks. I've learned it _____ heart.